Blender Git Loki

Fixes for offscreen drawing context on macOS.

* Disable multithreaded OpenGL again, it crashes on startup.
* Fix wrong clear context call in GHOST.
* Add GPU_state_init() also for draw context, just to be sure.
* Main fix: add glFlush() to avoid unfinished draw before leaving context.

merged collada rework from master into blender 2.8

rna build fix (error when building debug)

changing collada parameters

Differential Revision: https://developer.blender.org/D3080

Replace Use Dots for a Enum menu

Instead to define a checkbox, now the dots is a mode.

Apply strength factor to textured strokes

Adapt render code after merge

Again, the function parameter list has changed in Draw Manager and the gpencil code need changes.

Fix a whitespace slipped in

Merge branch 'blender2.8' into greasepencil-object

Conflicts:
source/blender/draw/intern/draw_manager.c

Add UV rotation option to Smooth and Noise modifiers

To be consistent, the modifiers must work with UV rotation as the sculpt brushes do.

only calc FM mblur velocity layer at render time

this costs some performance

Fix Plyer tm

T45687: Rework the Export/Import of Animations

This started with a fix for an animated Object Hierarchy. Then i decided to cleanup and optimize a bit. But at the end this has become a more or less full rewrite of the Animation Exporter. All of this happened in a separate local branch and i have retained all my local commits to better see what i have done.

Brief description:

* I fixed a few issues with exporting keyframed animations of object hierarchies where the objects have parent inverse matrices which differ from the Identity matrix.
* I added the option to export sampled animations with a user defined sampling rate (new user interface option)
* I briefly tested Object Animations and Rig Animations.

What is still needed:

* Cleanup the code
* Optimize the user interface
* Do the Documentation

Reviewers: mont29

Reviewed By: mont29

Differential Revision: https://developer.blender.org/D3070

Merge branch 'master' into blender2.8

Conflicts:
source/blender/blenkernel/BKE_blender_version.h

Smoke: expose empty space clipping property to the UI.

This is used to determine which voxels are to be considered empty space.

Previously it was hardcoded for converting dense grids to OpenVDB grids
to reduce disk space usage.

This value is also useful for rendering engines to know, i.e. to
optimize ray marching.

OpenVDB : use underscores instead of spaces in grid names.

Some other software cannot handle grid names with spaces in them. We still check for names with spaces so as to not break old
files.

This fixes T53802.

optionally restore old activation behavior with broken constraints

this allows easier breaking / collapsing of objects

GHOST: OSX: Make OGL 3.3 core profile defaults.

We are using 3.3 features for Blender 2.8. There is no other choice.

GHOST: OSX: Force opengl multithread initialisation.

This may not be what I think it is. But it might solve some problems we are having with DrawManager and separate contexts.

GHOST: GLX: Use a pbuffer for offscreen context.

Some implementation does not work well with offscreen context without a drawable surface.